See below for several steps to getting the water heater to work:

1.  Dead or Wont Ignite
   1. Check fuse in panel breaker box – These are the small 12 volt DC automobile style fuses
   2. 12 Volt power present (car style battery on camper) ? Check lights, fresh water pump, slide-outs, leveling jacks
      1. If no power then you need to plugin to shore power, running vehicle or generator to charge the 12 Volt battery.
2. Do you have propane and is it turned on?
   1. Confirm by turning on a stove-top burner.
   2. If the burner wont light that means there is no propane flowing.
3. Intermittent Hot water / Hot than cold or luke warm
   1. Check to make sure bypass valve is off (typically means its horizontal)
   2. Check outdoor shower. Hot and cold my be turned on with valve on handle turned off
4. Gas Burner Assembly
   1. May be small insect in orfice or burner assembly
   2. May be rust blocking burner assembly
5. Misc:
   1. Water heater can run off electrical and propane heating function at the same time for quicker recovery.
   2. Water heater is only 6 gallons or so. You can run out quickly use sparingly.
   3. Use shower handle shutoff valves to conserve water during shower.